Retirement Plans - Other (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) employee item	Dec. 31, 2018 USD ($)
Projected benefit obligation:
Balance, beginning of the year	$ 2,362	$ 2,242
Service cost	88	89
Interest cost	90	74
Actuarial loss (gain)	291	(43)
Benefits paid to participants	(194)
Balance, end of year	2,637	2,362
Funded status of the plan
Excess of benefit obligation over the value of plan assets	(2,637)	(2,362)
Unrecognized net actuarial loss	575	290
Unrecognized prior service cost	28	36
Accrued benefit cost	(2,034)	(2,036)
Net amounts recognized in the consolidated balance sheets
Accrued benefit cost	(2,637)	(2,362)
Accumulated other comprehensive loss	603	326
Accrued benefit cost	(2,034)	$ (2,036)
Benefits expected to be paid in each of the next five years and thereafter
2020	182
2021	334
2022	184
2023	149
2024	114
2025 through 2029	760
Total	$ 1,723
Weighted-average rates used
Discount rate on the benefit obligation (as a percent)	2.84%	3.96%
Pension expense
Service cost	$ 88	$ 89
Interest cost	90	74
Amortization of prior service cost	8	8
Net loss amortization	6	14
Net periodic benefit cost	$ 192	$ 185
Minimum
Weighted-average rates used
Rate of employee compensation increase (as a percent)	1.75%	1.75%
Maximum
Weighted-average rates used
Rate of employee compensation increase (as a percent)	2.50%	2.50%
WAPA
Number of months to be in service for applicability of retirement plan	3 months
Number of weeks per year of service for one-time lump sum payment at retirement	14 days
Maximum number of retirees per year under the plan | employee	5
Number of retirees per year under the retirement plan | item	154
WAPA | Maximum
Number of weeks per year of service for one-time lump sum payment at retirement	315 days